A conventional prior art photovoltaic cell includes a p-n diode. A depletion zone forms at the p-n junction, creating an electric field. Incident photons will knock electrons from the valence band to the conduction band, creating free electron-hole pairs. Within the electric field at the p-n junction, electrons tend to migrate toward the n region of the diode, while holes migrate toward the p region, resulting in current called photocurrent. Typically the dopant concentration of one region will be higher than that of the other, so the junction is either a p+/n− junction or a n+/p− junction. The more lightly doped region is known as the base of the photovoltaic cell, while the more heavily doped region, of opposite conductivity type, is known as the emitter. Most carriers are generated within the base, and it is typically the thickest portion of the cell. The base and emitter together form the active region of the cell. The cell also frequently includes a heavily doped contact region in electrical contact with the base, and of the same conductivity type, to improve current flow. Improved methods and apparatus are needed to produce photovoltaic cells that are useful in a variety of configurations.